Assessing buried infrastructure deep under buried infrastructure
In preparing for its water future, the Region of Peel (Peel) adopts a unique assessment strategy for a newly constructed potable water transmission main that extends deep underground through the heart of Peel Region. The effort is paying off, with Peel decision makers gaining a better understanding of this pipeline as it comes into service.
Peel Water & Wastewater services approximately 1.3 million residents and 88,000 businesses in Brampton, Caledon and Mississauga. The Hanlan Water Project is the largest water pipeline capital initiative ever undertaken by Peel, with a cost of approximately $500 million. The completed transmission and sub-transmission mains included in the Hanlan Water Project will serve Peel’s growth projections for the next two decades.
The project includes 15 km of 2400mm (96-inch) PCCP water transmission main. Construction began in 2011 and is scheduled for completion by 2017. The project is split into three contracts and construction includes both tunnelling and open-cut methods.
Some pipeline sections tunneled in excavated depths of 50 meters
The project is unique from the point of view that the majority of the pipeline will be built under existing infrastructure, with some sections of pipeline tunnelled in excavated depths up to 50 meters (150 feet).
Peel has encouraged the use of technology and innovation throughout this project and has included innovative assessment strategies by Pure Technologies (Pure) prior to pipeline commissioning. Baseline condition assessment and real-time monitoring technologies have offered value, and peace of mind to Peel managers and decision makers involved with this project.
Pure’s baseline condition assessment includes visual inspection, 3D inertial mapping, electromagnetic (EM) inspection where applicable and SoundPrint® acoustic fiber optic (AFO) monitoring the pipeline during hydrostatic pressure testing of the pipeline. The project includes a continuous monitoring solution once the pipeline is commissioned into service, expected in 2017.
AFO monitoring is an innovative monitoring technology for identifying wire breaks in PCCP pipes. Unlike EM, which identifies the number of wire breaks that exist at a point in time, acoustic monitoring identifies the number of wire breaks that occur during the monitoring period, effectively identifying the location of active deterioration for the lifespan of the asset.
By ‘listening’ for wire breaks, pipes that are approaching failure can be identified and rehabilitated. With the installation of AFO technology at the time of construction, Peel ensures active management of their most valuable buried assets, for the life of the asset.
“A snapping wire or two won’t sound an alarm bell,” says Adam Koebel on behalf of the Data Analysis Group at Pure. “But when our monitoring team notices a large number of pings from the wires breaking in a concentrated location, that’s when we focus attention on the acoustic anomalies to determine whether remedial action needs to take place.”
The project was split into 3 contracts with varying scope per contract
The 15 km of 2400mm PCCP project was split into 3 contracts with different general contractors, and complimentary scope per contract.
Contract 2 (conducted first) included visual and sounding, inertial mapping, EM and AFO
Upon completion of the 2400mm pipeline construction along a busy section of Dixie Road, Pure conducted an electromagnetic inspection to scan for potential pipeline problems that may have occurred during construction (or during the manufacturing process). This assessment included GIS mapping using a 3D Inertial Mapping Unit (IMU) to digitally map the precise position of this new main. Pure installed its proprietary SoundPrint® Acoustic Fiber Optic (AFO) technology to listen, identify and locate any possible wire wrap breaks during the hydrostatic pressure test of this section.
The acoustic monitoring covered a distance of 1,138 meters and spanned a total of 132 pipe sticks. Analysis of the data recorded during the pipeline monitoring found two (2) acoustic anomalies consistent with wire wrap breaks, which amounts to a negligible amount of change or distress. Pure conducted a second (post pressure test) EM scan to confirm the AFO testing and determine the presence of pipe wall distress.
Contract 1 (underway) includes visual inspection and mapping
Pure’s involvement in Contract 1 began in 2016, with a visual and sounding inspection of 5.87 km of the 2400m PCCP pipeline and included identifying potential joint defects and other signs of distress, as well as verifying lay schedule from within the pipe. AFO monitoring will let Peel and their contractor know if any distress occurred during hydrostatic testing.
Contract 3 is on schedule to wrap-up in 2017, while Contract 4 scope of work will include final disinfection and commissioning of the new feedermain.
Once a baseline condition has been established, the AFO system will allow Peel to track the deterioration rate and identify at-risk pipes before they fail. For Peel, acoustic fiber optic monitoring is like preventative medicine, and as a safeguard, it’s proven to work.